18 Diameter by 2 High Foamrush Premium Quality - Etsy
FoamRush 9" Diameter x 22" Long Round Bolster Memory Foam Roll Insert Replacement (Ideal for Home Accent Décor Positioning and General Fitness) - Walmart.com
FoamRush 5" Height x 35" Width x 45" Length Upholstery Foam Cushion High Density - Walmart.com